1. Field of the Invention
This invention relates to an improved construction for tandem rolling mills and, more specifically, it relates to such improvements which may advantageously be employed in hot strip mills.
2. Description of the Prior Art
It has been know, in connection with various types of multi-stand rolling mills, to provide variations in the diameter of the rolls so as to achieve certain objectives.
In the interest of facilitating ease of maintenance construction and interchangeability of parts, it has been known to provide tandem rolling mills wherein the rolls of successive stands are of the same diameter.
U.S. Pat. No. 3,645,121 which relates to the rolling of tubular stock, discloses a system wherein the work rolls are of progressively larger diameter. U.S. Pat. No. 3,877,275 discloses a cold roll reduction mill which is adapted to form various structural members and has rolls of diameter increasing in the downstream direction.
U.S. Pat. No. 1,946,240 after stating that it was known in the prior art to successively decrease the diameters of rolls in the hot rolling of steel strips, suggests the use of rolls of the same diameter for most or all of the rolling stations, and, also teaches the use of increased distance between sequentially positioned pairs of rolls in the downstream direction.
U.S. Pat. No. 3,861,188 discloses roll systems for forming checkered thin plates and teaches the use in certain stands of one work roll of a different diameter from the other.
U.S. Pat. No. 2,139,872 discloses the use of opposed rolls of different diameter and sequential reduction in diameter of both the work rolls and the backup rolls in a downstream direction.
U.S. Pat. No. 4,479,374 discloses roll length being reduced sequentially in a downstream direction.
U.S. Pat. No. 1,810,167 discloses reduction in diameter of work rolls in a downstream direction combined with increased spacing between successive roll stands in a downstream direction.
In spite of the foregoing disclosures, there remains a need for improved tandem rolling mill constructions wherein the relationships between roll diameters, spacing between adjacent stands and roll length may be combined so as to maximize efficiency of operation of the mill.